Time-of-Flight (ToF) distance measurements between a ToF camera and an object are based on active illumination. The distance measurement accuracy is a function of light energy that is transmitted by the ToF camera. However, the maximum light energy is limited by eye and skin safety standards.
Existing solutions allow only a few ToF camera settings which are known to be safe. The exposure time, which is the time during which the ToF camera is transmitting and receiving light, is limited to a predetermined time period which cannot be exceeded. Some advanced modulation schemes allow longer exposure times because the average light energy transmitted by the ToF camera is lower than the maximum permissible value. Additionally, some ToF cameras include a monitoring circuit configured to monitor the transmitted light and shut down the ToF camera when the transmitted light energy exceeds a predetermined value. The performance of the ToF camera is therefore limited.